Micro-alloyed manganese-boron steel

ABSTRACT

A micro-alloyed manganese-boron steel includes about 0.25 to 0.4 wt. % carbon, about 0.5 to 2.7 wt. % manganese, about 0.001 to 0.005 wt. % boron, about 0.1 to 0.8 wt. % silicon, about 0.1 to 0.6 wt. % chromium, molybdenum and nickel, and about 0.01 to 0.06 wt. % aluminum, niobium and titanium. The balance is iron, and the steel is a micro-alloyed material for hot stamping of automotive parts.

TECHNICAL FIELD

The disclosure relates to a manganese-boron steel micro-alloyed with oneor more additives, and optionally coated, for hot stamping and a methodof producing and using the same.

BACKGROUND

The requirements for high security, low weight, and good fuel economyhave become increasingly important in automotive manufacturing. To meetall of these requirements, high strength steels have become increasinglypopular in vehicle body manufacturing to improve crash behavior and atthe same time lower the weight of the vehicle. The high strength steelsmay be produced at room temperature by cold stamping or at hightemperatures at which the material is austenized. The latter processcalled hot stamping is a non-isothermal forming process for sheet metal,where forming and quenching take place in the same step. In comparisonto components manufactured by the cold stamping process, hot stamping iscapable of providing components having minimum springback, reduced sheetthickness, and superior mechanical properties such as high strength. Avariety of press hardening steel grades have been developed for the hotstamping process.

SUMMARY

In at least one embodiment, a micro-alloyed manganese-boron steel isdisclosed. The micro-alloyed manganese-boron steel includes about 0.25to 0.4 wt. % carbon, about 0.5 to 2.7 wt. % manganese, about 0.001 to0.005 wt. % boron, about 0.1 to 0.8 wt. % silicon, about 0.1 to 0.6 wt.% chromium, molybdenum, and nickel, and about 0.01 to 0.06 wt. %aluminum, niobium, and titanium, the balance being iron and the steelbeing a micro-alloyed material for hot stamping of automotive parts. Thesteel may further include up to about 0.01 wt. % sulfur, vanadium, orboth. The steel may further include up to about 0.01 wt. % nitrogen. Thesteel may also include up to about 0.03 wt. % phosphorus. The steel maybe coated with an aluminum silicon coating. The coating may be AlSi10Fe3coating.

In an alternative embodiment, a hot stamping method is disclosed. Themethod includes forming a hot stamped automotive component from amicro-alloyed manganese-boron steel blank comprising about 0.25 to 0.4wt. % carbon, about 0.5 to 2.7 wt. % manganese, about 0.001 to 0.005 wt.% boron, about 0.1 to 0.8 wt. % silicon, about 0.1 to 0.6 wt. %chromium, molybdenum, and nickel, about 0.01 to 0.06 wt. % aluminum,niobium, and titanium, and a balance of iron, by hot stamping such thatthe component reaches a minimum yield strength of 1400 MPa at the end ofthe hot stamping process. The micro-alloyed manganese-boron steel blankmay also include up to about 0.01 wt. % nitrogen. The blank may furtherinclude up to about 0.01 wt. % sulfur, vanadium, or both and/or up toabout 0.03 wt. % phosphorus. At the end of the quenching operation, andprior to baking in a paint oven, the hot stamped component may have aminimum tensile strength of about 1800 MPa. At the end of the quenchingoperation, and prior to baking in a paint oven, the hot stampedcomponent may have a minimum total elongation of about 6%. Themicro-alloyed manganese-boron steel may be coated with an aluminumsilicon coating. The method may also include exposing the hot stampedcomponent to elevated temperatures in a paint baking over to increaseyield strength beyond the 1400 MPa. The end of the hot stampingoperation includes releasing the component after quenching operation.

In a yet different embodiment, a hot stamped component is disclosed. Thecomponent includes a micro-alloyed manganese-boron steel including about0.25 to 0.4 wt. % carbon, about 0.5 to 2.7 wt. % manganese, about 0.001to 0.005 wt. % boron, about 0.1 to 0.8 wt. % silicon, about 0.1 to 0.6wt. % chromium, molybdenum, and nickel, and about 0.01 to 0.06 wt. %aluminum, niobium, and titanium, the balance being iron, and has aminimum yield strength of at least 1400 MPa. The component may be a bodyin white automotive part. The component may be a side beam. Thecomponent, at an end of hot stamping, has a minimum tensile strength ofabout 1800 MPa. The component, at the end of the hot stamping process,at an end of hot stamping, has a minimum total elongation of about 6%.The micro-alloyed manganese-boron steel may be coated with an aluminumsilicon coating.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an exemplary schematic view of a hot stamping system andprocess in accordance with one or more embodiments;

FIG. 2 depicts a schematic perspective side view of an exemplary hotstamping press incorporated in the hot stamping system depicted in FIG.1;

FIG. 3 shows an example automotive component produced from the steeldisclosed herein by a hot stamping process such as the hot stampingprocess of FIG. 1.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described herein. It is to beunderstood, however, that the disclosed embodiments are merely examplesand other embodiments may take various and alternative forms. Thefigures are not necessarily to scale; some features could be exaggeratedor minimized to show details of particular components. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but merely as a representative basis forteaching one skilled in the art to variously employ the presentinvention. As those of ordinary skill in the art will understand,various features illustrated and described with reference to any one ofthe figures may be combined with features illustrated in one or moreother figures to produce embodiments that are not explicitly illustratedor described. The combinations of features illustrated providerepresentative embodiments for typical applications. Variouscombinations and modifications of the features consistent with theteachings of this disclosure, however, could be desired for particularapplications or implementations.

Except where expressly indicated, all numerical quantities in thisdescription indicating dimensions or material properties are to beunderstood as modified by the word “about” in describing the broadestscope of the present disclosure.

The first definition of an acronym or other abbreviation applies to allsubsequent uses herein of the same abbreviation and applies mutatismutandis to normal grammatical variations of the initially definedabbreviation. Unless expressly stated to the contrary, measurement of aproperty is determined by the same technique as previously or laterreferenced for the same property.

Reference is being made in detail to compositions, embodiments, andmethods of the present invention known to the inventors. However, itshould be understood that disclosed embodiments are merely exemplary ofthe present invention which may be embodied in various and alternativeforms. Therefore, specific details disclosed herein are not to beinterpreted as limiting, rather merely as representative bases forteaching one skilled in the art to variously employ the presentinvention.

The description of a group or class of materials as suitable for a givenpurpose in connection with one or more embodiments of the presentinvention implies that mixtures of any two or more of the members of thegroup or class are suitable. Description of constituents in chemicalterms refers to the constituents at the time of addition to anycombination specified in the description, and does not necessarilypreclude chemical interactions among constituents of the mixture oncemixed. The first definition of an acronym or other abbreviation appliesto all subsequent uses herein of the same abbreviation and appliesmutatis mutandis to normal grammatical variations of the initiallydefined abbreviation. Unless expressly stated to the contrary,measurement of a property is determined by the same technique aspreviously or later referenced for the same property.

Hot stamping, also called hot forming or press hardening, is a processof forming metal while the metal is very hot, usually in excess of 900°C., and subsequently quenching the formed metal in a closed die. Hotstamping may be direct or indirect. The hot stamping process convertslow-tensile-strength metal to a very high-strength metal of about 150 to230 kilo pounds per square inch (KSI). During a typical hot stampingprocess, schematically depicted in FIG. 1, a press-hardenable materialis heated as a blank 10 to about 900 to 950° C. to an austenite state inthe first stage of the press line or hot stamping system 22. The firststage lasts for about 4 to 10 minutes inside of a continuous-feedfurnace 12. A robot transfer system 14 subsequently transfers theaustenized blank 10 to a press 16 having a die arrangement 18. Thetransfer usually takes less than 3s. A part 20 is formed in the diearrangement 18 from the blank 10 while the material is very hot. Theblanks 10 are stamped and cooled down under pressure for a specificamount of time according to the sheet thickness after drawing depth isreached. During this period, the formed part 20, further also referredto as a component 20, is quickly cooled or quenched by being held in aclosed die cavity having a water cooling system. Quenching is providedat a cooling speed of 50 to 100° C./s for a few seconds at the bottom ofthe stroke, which is when the material's grain structure is convertedfrom the austenitic state to a martensitic state. Finally, the component20 leaves the hot-stamping line at about 150° C.

Typically, the component 20 has relatively high mechanical properties:tensile strength of about 1,400 to 1,600 MPa (200 to 230 KSI) or higherand a yield strength of about 1,000 and 1,200 MPa (145 to 175 KSI) orhigher. The component 20 may be further treated and/or processed, forexample incorporated in the body in white (BIW), provided with one ormore coatings, baked in a paint oven, or the like.

The hot stamping process provides numerous advantages over otherhigh-strength steel and advanced high-strength steel forming methodssuch as cold stamping. One of the advantages is providingstress-relieving capability which resolves problems such as springbackand warping typically associated with other high-strength steel formingmethods. Additionally, hot stamping allows the forming of complex partsin a single-step die and in only one stroke. Thus, multi-componentassemblies can be redesigned and formed as one component, eliminatingdownstream joining processes such as welding and eliminating the needfor additional parts. This may, in turn, reduce overall mass of theformed parts.

Hot stamped parts 20 have found broad application in automotiveindustry. Typically, hot stamping is best-suited to form componentswhich are required to be both lightweight and strong at the same time.Exemplary automotive components formed by hot stamping include bodypillars, rockers, roof rails, bumpers, door intrusion beams, carrierunderstructure, mounting plates, front tunnels, front and rear bumpers,reinforcement members, side rails, and other auto parts that arerequired to be strong enough to withstand a large load with minimalintrusion into the passenger compartment during a rollover and impact.Hot stamping thus enables producing such components meeting structuralperformance requirements while adding as little weight to a vehicle aspossible.

Yet, to provide high quality hot stamped parts, a suitable materialneeds to be used. A plethora of various steel grades for hot stampinghas been developed. For example, Usibor® 1500, Ductibor® steel grades,and the like. Manganese-boron steel grades such as 22MnB5 have alsobecome common in hot stamping.

Manganese-boron steels are tempered boron-alloy steels. They usuallyfeature good formability and good strength after heat treatment. Thedesirable strength of the manganese-born steel grades is at lastpartially due to their content of carbon and manganese, and a lowcontent of boron, which is typically not more than a few thousandths ofa percent. Example manganese-boron steels and their compositions arelisted in FIG. 1 below. Weight percent of individual elements is basedon an overall weight of the material, the balance being iron.

TABLE 1 Chemical composition of example manganese-boron steels Steel C BCr Mn Si max P max S max grade [wt. %] [wt. %] [wt. %] [wt. %] [wt. %][wt. %] [wt. %] 8MnCrB3 0.06-0.11 0.0008-0.0040 0.25-0.5   0.7-1.00 0.40.025 0.025 17MnB3 0.15-0.18 0.0008-0.0045 0.15-0.35 0.6-0.8 0.4 0.0250.025 20MnB5 0.17-0.23 0.0008-0.0050 — 1.1-1.4 0.4 0.025 0.025 22MnB50.19-0.26 0.0008-0.0050 0.15-0.35 1.1-1.4 0.4 0.025 0.025 30MnB50.27-0.33 0.0008-0.0050 — 1.15-1.45 0.4 0.025 0.025 37MnB5 0.34-0.400.0008-0.0050 0.15-0.35 0.8-1.1 0.4 0.025 0.025 38MnB5 0.36-0.420.0008-0.0050 — 1.15-1.45 0.4 0.025 0.025

To further improve mechanical properties of certain steel grades, thematerial may be electrically galvanized, hot-dip galvanized,galvannealed, or coated, for example with aluminum silicon coating.

Another technique to increase at least some mechanical properties ofsteel is micro-alloying. A micro-alloyed steel is a type of a low-carbonalloy steel containing small amounts of alloying elements or additives,such as 0.05-0.15 wt. %, based on the total weight of the steelmaterial, besides about 0.06 or lower-0.12 wt. % carbon and up to 0.2wt. % manganese. The elements used for microalloying may be niobium,vanadium, titanium, molybdenum, zirconium, boron, rare-earth metals, ora combination thereof. Each element, its amount, and overall compositionof the steel may influence different properties of the steel.

The micro-alloyed steels derive their strength from precipitationhardening. The elements are used to refine the grain microstructure ofthe steel grade, facilitate precipitation hardening, or both.Specifically, the micro-alloying elements combine with carbon and/ornitrogen and precipitate to strengthen the ferrite phase. Usually, themicro-alloyed steels have a good weldability and notch toughness, whichmay be further improved by reducing the carbon content. Other beneficialproperties typically include good fatigue life and wear resistance whichmay be superior to heat-treated steels. As the micro-alloyed steels arenot quenched and tempered, they are not susceptible to quench crackingand do not require straightening or stress relieving.

Despite existence of available steel grades, a need remains for a steelmaterial suitable for the hot stamping process which would have veryhigh strength levels of up to about 2000 MPa tensile strength. Yet, itwould be desirable that such material may be used in a conventional hotstamping process, for example when applying a production hot stampingschedule for press hardening of PHS1500 AlSi10Fe3 coated steel grade,while meeting the following target mechanical properties: minimum yieldstrength of about 1400 MPa, minimum tensile strength of about 1800 MPa,and minimum elongation of about 6% total elongation after die quenchingand preferably before the paint baking process. For example, a steelgrade 36MnB5 or 36MnB5 coated with AlSi10Fe3, which are currently beingused, do not meet the target properties.

Thus, there remains a need for a manganese-boron steel grade to meet thetarget mechanical properties prior to the paint baking process, withoutrelying on the effect of the paint baking process during the hotstamping processing and post-processing. Additionally, using steelgrades such as 36MnB5 may impose additional constraints on the hotstamping parameters such as die temperature below 100° C., increase ofdie dwell time, increase of the die contact pressure, and/or otheradjustments to the process and equipment which may result in overallincreased capital investments associated with the production of the hotstamped parts with materials such as 36MnB5.

In one or more embodiments, a manganese-boron alloy steel overcoming oneor more problems described above is disclosed. The manganese-boron alloysteel may include the following elements or additives listed in Table 2.Weight percent of individual elements is based on an overall weight ofthe material, the balance being iron. Incidental elements commonly foundin steelmaking practice are acceptable, as long as they do not soadversely affect the steel that it cannot meet the target mechanicalproperties.

TABLE 2 The manganese-boron alloy steel composition in weight percentelement C [wt. Mn Si Cr Mo Ni S amount %] [wt. %] [wt. %] [wt. %] [wt.%] [wt. %] [wt. %] Min 0.25 0.5 0.1 0.1 0.1 0.1 0.0 Max 0.40 2.7 0.8 0.60.6 0.6 0.01 element Al [wt. Nb Ti V N P B amount %] [wt. %] [wt. %][wt. %] [wt. %] [wt. %] [wt. %] Min 0.01 0.01 0.01 0.0 0.0 0.0 0.001 Max0.06 0.06 0.06 0.01 0.01 0.03 0.005

The carbon content of the steel may be from about 0.25 to 0.4 wt. %, 0.8to 3.5 wt. %, or 0.3 to 3.2 wt. %. Lower amount than about 0.25 wt. %may result in insufficient tensile strength of the steel. The amount ofcarbon above about 0.4 wt. % may, on the other hand, negativelyinfluence elongation.

Manganese may be present in the amount of about 0.5 to 2.7 wt. %, 1 to2.5 wt. %, or 1.5 to 2 wt. %. Boron may be present in the amount of0.001 to 0.005 wt. %, 0.002 to 0.005 wt. %, or 0.003 to 0.004 wt. %.Manganese may be added together with sulfur as manganese sulfideinclusions.

The microalloying elements such as sulfur, vanadium, and nitrogen may bepresent in the amount of 0.0 to 0.01 wt. %, 0.0025 to 0.008 wt. %, or0.005 to 0.0075 wt. %. The content of chromium, molybdenum, and nickelmay be from 0.1 to 0.6 wt. %, 0.2 to 0.5 wt. %, or 0.3 to 0.4 wt. %. Thecontent of aluminum, niobium, and titanium may be from 0.01 to 0.06 wt.%, 0.02 to 0.05 wt. %, or 0.03 to 0.04 wt. %. The amount of silicon maybe 0.1 to 0.8 wt. %, 0.2 to 0.6 wt. %, or 0.4 to 0.5 wt. %. The contentof phosphorus may be 0.0 to 0.3 wt. %, 0.05 to 0.2 wt. %, or 0.075 to0.1 wt. %. Vanadium, nitrogen, and phosphorus may or may not be present.

The disclosed steel may comprise the components in Table 2.Alternatively, the disclosed steel may consist of or consist essentiallyof the elements listed in Table 2.

The focus of the disclosure is to form a manganese-boron steel,micro-alloyed with addition of different proportions of chemicalelements listed in Table 2 such that the alloyed steel may be stampedinto an automotive component or part 20 by a hot stamping process suchthat the part 20 has a minimum yield strength of at least about 1400MPa, about 1400 MPa, or 1400 MPa, minimum tensile strength of at leastabout 1800 MPa, about 1800 MPa, or 1800 MPa, and minimum elongation ofat least about 6%, about 6%, or 6% total elongation right after, or atthe end of, a die quenching operation of the hot stamping processwithout any contribution of the paint baking process. The paint bakingprocess may follow the hot stamping process immediately, shortly, oreventually after the hot stamping process is finished.

Without limiting the disclosure to a single theory, it is anticipatedthat both the composition and the thermal processing results in amaterial capable of meeting the target values listed above. The yieldstrength of the formed alloyed steel meets the target prior to paintbaking, and the contribution of precipitation strengthening anddislocation density components to the material yield strength throughthe effect of the paint baking process is thus only optional and couldserve as an additional mechanism, further increasing the yield strengthof the material, but is not a necessity. Additional advantages of thedisclosed steel grade may be elimination of the mentioned constraints onthe hot stamping parameters as well as financial savings.

By adding the elements of Table 2 to the manganese-boron steel, thecontribution of solid solution strengthening component is increasedwhile the benefit and the contribution of the grain size component tothe material yield strength is maintained. Alloying the elements listedin Table 2 enables the precipitates to be taken into the solution duringthe heating and soak stages (quenching), remain in the solution duringhot working, and precipitate to strengthen the ferrite during cooling.To enable effective precipitation, the growth of the precipitates shouldnot exceed a size at which they would not provide strengthening.Precipitation strengthening may lead to lower ductility and impactresistance. Yet, the precipitation may be used to control the austeniticgrain size and ferrite grain size after transformation.

The austenitic grain size may be controlled, for example, by restrainingthe austenitic grain growth during the soak, using a dispersion such asfine TiN which remains undissolved at the soak temperature, or choosinga precipitate capable of inhibiting the rate of recrystallization of theaustenite.

The method of production of the disclosed steel also influences thesteel properties. The method may include forming an initial alloyingmaterial from the base steel material with the elements or microalloyingadditives listed above. The base steel material is a manganese-boronsteel material. The base steel may be Mn36B5 steel base material. Thebase steel material includes iron ore and coal. The coal may be cleanedof impurities in a coke oven to yield an almost pure form of carbon.

The method may include heating a mixture of the base steel material andthe microalloying additives, melting the mixture, and homogenizing thesteel molten material. The melting may be provided in a blast furnace.The method may include processing the steel from the steel moltenmaterial in an oxygen converter, an open hearth, an electric arcfurnace, a cyclone converter furnace, or a different apparatus. Themethod may include secondary steelmaking processes such as stirring,ladle furnace, ladle injection, degassing, composition adjustment,oxygen blowing, or the like. The method also includes ingot orcontinuous casting such that the molten steel material is cast into acooled mold causing a thin steel shell to solidify. The strand may becut into desired lengths such as thin strips. The micro-alloyed steelmay be subsequently forged by hot-rolling, which helps eliminate castdefects and achieve a desired shape and surface quality. Hot rolling maybe followed by cold-rolling in ambient air without an additional heattreatment. The rolled sheets may feature ferritic-pearliticmicrostructure which is transformed to fully martensitic structure afteror during the hot stamping process.

The steel may be also coated to enhance certain properties such astolerance of temperatures of up to 800° C. without scaling,delamination, or both, or to increase corrosion resistance. The coatingmay be, for example, aluminum silicon coating. The coating may beAlSi10Fe3 coating.

The method includes using the steel disclosed herein in the blank 10 ofthe hot stamping process described above to form one or more hot stampedparts. The one or more hot stamped parts may be a part for automotiveapplications such as high tensile strength automobile parts 20 meetingor exceeding the target properties named above. The part 20 may be afront bumper, tail bumper, A column, B column, C column, roof frame,floor frame, door panel, door anti-beam, intrusions beams, body pillars,rockers, mounting plates, front tunnels, side rails, reinforcementmembers, and other parts in BIW, or the like, example of which is shownin FIG. 3.

At the end of the hot stamping cycle, and prior to being exposed toadditional high temperatures such as for example in a paint baking oven,the component or part 20 made from the disclosed steel material has aminimum yield strength of at least about 1400 MPa or about 1400 MPa, or1400, 1410, 1420, 1430, 1440, 1450, 1480, 1500, 1510, 1520, 1550, 1580,1600 MPa or higher; a minimum tensile strength of at least about 1800MPa or about 1800, 1810, 1820, 1830, 1840, 1850, 1870, 1890, 1900, 1920,1940, 1950, 1960, 1980, 2000 MPa, and minimum elongation of at leastabout 6% or about 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7.0,7.1, 7.2, 7.3, 7.4, 7.5, 7.7, 7.9, 8.0, 8.1, 8.5, 9.0, 9.5. 10, 10.5,11% or more total elongation.

The end of the hot stamping cycle or operation is the release of thepart 20 after quenching such when the part 20 leaves the hot-stampingline at about 150° C. Paint baking is not a part of the hot stampingprocess, but a subsequent process or operation. The paint baking processmay follow the hot stamping process immediately, shortly, or eventuallyafter the hot stamping process is finished. The paint baking may furtherimprove the properties named above by exposing the part 20 to elevatedtemperatures. The elevated temperatures include temperatures needed tocure one or more coatings such as one or more layers of automotivepaint.

While exemplary embodiments are described above, it is not intended thatthese embodiments describe all possible forms of the disclosure. Rather,the words used in the specification are words of description rather thanlimitation, and it is understood that various changes may be madewithout departing from the spirit and scope of the disclosure.Additionally, the features of various implementing embodiments may becombined to form further embodiments of the disclosure.

1. A micro-alloyed manganese-boron steel comprising: about 0.25 to 0.4wt. % carbon; about 0.5 to 2.7 wt. % manganese; about 0.001 to 0.005 wt.% boron; about 0.1 to 0.8 wt. % silicon; about 0.1 to 0.6 wt. %chromium, molybdenum and nickel; and about 0.01 to 0.06 wt. % aluminum,niobium and titanium; the balance being iron, and the steel being amicro-alloyed material for hot stamping of automotive parts.
 2. Themanganese-boron steel of claim 1, further comprising up to about 0.01wt. % sulfur, vanadium or both.
 3. The manganese-boron steel of claim 1,further comprising up to about 0.01 wt. % nitrogen.
 4. Themanganese-boron steel of claim 1, further comprising up to about 0.03wt. % phosphorus.
 5. The manganese-boron steel of claim 1, wherein thesteel is coated with an aluminum silicon coating.
 6. The manganese-boronsteel of claim 5, wherein the coating comprises AlSi10Fe3.
 7. A hotstamping method comprising: forming a hot stamped automotive component,from a micro-alloyed manganese-boron steel blank comprising about 0.25to 0.4 wt. % carbon, about 0.5 to 2.7 wt. % manganese, about 0.001 to0.005 wt. % boron, about 0.1 to 0.8 wt. % silicon, about 0.1 to 0.6 wt.% chromium, molybdenum and nickel, about 0.01 to 0.06 wt. % aluminum,niobium and titanium, and a balance of iron, by hot stamping such thatthe component reaches a minimum yield strength of 1400 MPa at an end ofhot stamping.
 8. The method of claim 7, wherein the micro-alloyedmanganese-boron steel blank further comprises up to about 0.01 wt. %nitrogen.
 9. The method of claim 7, wherein the micro-alloyedmanganese-boron steel blank further comprises up to about 0.01 wt. %sulfur, vanadium, or both and/or up to about 0.03 wt. % phosphorus. 10.The method of claim 7, wherein at an end of a quenching operation, andprior to baking in a paint oven, the hot stamped component has a minimumtensile strength of about 1800 MPa.
 11. The method of claim 7, whereinat an end of a quenching operation, and prior to baking in a paint oven,the hot stamped component has minimum total elongation of about 6%. 12.The method of claim 7, further comprising coating the micro-alloyedmanganese-boron steel with an aluminum silicon coating.
 13. The methodof claim 7, further comprising exposing the hot stamped component toelevated temperatures in a paint baking oven to increase yield strengthbeyond the 1400 MPa.
 14. The method of claim 7, wherein the end of thehot stamping includes releasing the component after quenching.
 15. A hotstamped component comprising: a micro-alloyed manganese-boron steelincluding about 0.25 to 0.4 wt. % carbon, about 0.5 to 2.7 wt. %manganese, about 0.001 to 0.005 wt. % boron, about 0.1 to 0.8 wt. %silicon, about 0.1 to 0.6 wt. % chromium, molybdenum and nickel, andabout 0.01 to 0.06 wt. % aluminum, niobium and titanium, the balancebeing iron, and having a minimum yield strength of at least 1400 MPa.16. The hot stamped component of claim 15, wherein the component is abody in white automotive part.
 17. The hot stamped component of claim15, wherein the component is a side beam.
 18. The hot stamped componentof claim 15, wherein the component, at an end of hot stamping, has aminimum tensile strength of about 1800 MPa.
 19. The hot stampedcomponent of claim 15, wherein the component, at an end of hot stamping,has a minimum total elongation of about 6%.
 20. The hot stampedcomponent of claim 15, wherein the micro-alloyed manganese-boron steelis coated with an aluminum silicon coating.